what should i do to to evaluate the total length of a trajectory obtained as the sum of the distances of a point from the next??

Hello everyone, I'm working on my specialist degree thesis (Biomedical Engeenering) and I have to evaluate many parametres about length,velocity,acceleration,mean frequency and others. Expecially I need an Help for evaluating these parametres with Matlab ( I never used the programming language Matlab and I'm very worried about my work thesis ):

1. Item one: *the total length of a trajectory obtained as the sum of the distances of a point frome the next:*L=∑_(i=1)^(n-1)▒√(〖(AP[i+1]-AP[i])〗^2+〖(ML[i+1]-ML[i])〗^2 ) where AP (antero-posterior) and Ml(medio-lateral) represent 2 different directions where the points are localized.
2. Item two _ * The length AP is the sum of the absolute distances between two consecutive points towards AP direction*_Lap= ∑_(i=1)^(n-1)▒|AP[i+1]-AP[i]|

How this can be done on Matlab???? thanks in advance

Answer 1

[Thorsten]

If AP and ML are vectors, you can use

 L = sum(sqrt(diff(AP).^2 + diff(ML).^2));
 Lap = sum(abs(diff(AP)))

[giulia carboni]

AP(ì) is the point in a curve at position (i) in the Antero-posterior direction , AP(ì+1) is its following point. The same applies to medio-lateral direction (ML). any point has two coordinate like (x,y).

[Thorsten]

That's fine. Does it work for you as expected? Then please formally accept my answer.

[Torsten]

You overlooked that AP and ML are points with two coordinates x and y ...

Best wishes

Torsten.

[giulia carboni]

Could I use a For loop instead of sum.?